IntBuffer
A platform-agnostic IntBuffer built on top of a kotlin‑io Buffer.
The capacity is in numbers of ints (each int is 4 bytes). The position and limit are expressed in ints. When reading/writing, This version tracks an extra baseOffset (in bytes) so that view buffers (via slice()) share the same underlying Buffer while translating int indices appropriately.
All indices (position, limit, capacity) are in units of ints (4 bytes). we convert indices by multiplying by 4.